Of a period of time, or a process, state, or action: having a great extent in duration; occupying or requiring much time from beginning to end.

Long, lengthy, esp. excessively or tediously so; lasting or taking a long time.

long of life (in Old English lang līfes): possessing a long lifespan; long-lived. Now somewhat archaic.

Continuing, enduring; (also) of long continuance, permanent. In early use also (contextually): †everlasting, endless, eternal.

figurative. Abiding, lasting, persistent.

Always going on, incessant, perpetual; i.e. continuing without any intermission, continuous (in time); or less strictly, repeated with brief…

remaining, lasting, abiding.

That lives or exists for a long time.

Used hyperbolically or in a relative sense. Lasting for a very long time; existing from long ago or into the distant future. Cf. eternal, adj. 4.

that lasts or takes a long time; long-enduring.

That lasts a long time, enduring.

That has a long life or existence; that lives or lasts for a long time.

Of time. Obsolete.

Enduring, permanent; everlasting.

Lasting, enduring, permanent. Cf. perseverance, n. 1c. Obsolete.

Continuing or designed to continue or last indefinitely without change; abiding, enduring, lasting; persistent. Opposed to temporary.

Lasting; enduring or able to endure over a long period, esp. the course of human history or a lifetime.

Carried on or kept up without cessation; continual, constant.

Lasting, enduring; long-lived; permanent. Now usually modifying an abstract noun.

Of a quality, condition, etc., esp. one that is harmful or undesirable: not eliminated, done away with, or got rid of; not stopped, cancelled, or…

rhetorically. Said of things to which endless continuance is ascribed hyperbolically or in relative sense. Eternal City (Latin urbs æterna): a…

Continued or that has continued for a long period of time; long-lasting, prolonged.

That continues (in various senses of the verb); abiding, lasting; persistent, persevering.

That endures, lasting.

In hyperbolical use: Lasting, perpetual, constant, ‘undying’, ‘eternal’.

= diuturnal, adj.

Long-lasting, chronic; = veterate, adj. 1.

Resident, dwelling; abiding. In predicative use or as a postmodifier (sometimes in plural form). Of a thing (chiefly something immaterial).

In intransitive senses. With complement, as staying silent. Obsolete.

Able to withstand a great deal of wear or use; long-lasting, hard-wearing. Frequently of immaterial things.

That has a firm or solid basis; enduring; important, significant, weighty; of substantial extent or amount, considerable.

Of a state or thing: persistent, continuing; spec. (of a disease) resistant to treatment. Obsolete.

Continuing to exist; that has escaped the ravages of time, still existing.

Without ceasing, unceasing, uninterrupted.

figurative. Chiefly poetic. Enduring as marble, or as if carved in marble. Obsolete. rare.

The quality or fact of being long; opposed to shortness. †of length: long.

= longevous, adj.

Of long duration, lasting.

Of diseases, etc.: Lasting a long time, long-continued, lingering, inveterate; opposed to acute.

Not used up, expended, or brought to an end.

Of disease: = chronic, adj. 2.

Able or likely to endure, durable. rare.

Continuing, persisting in time, enduring; remaining in force.

Not ceasing to flourish, unfading: cf. deflourish, v. 2.

figurative and in extended use.

Lasting, continuing long.

Continued, long-continued, lasting, chronic.

= perennial, adj. (in various senses).

Living or lasting for an age or ages. Now chiefly with reminiscence of the scientific sense A. 7. Also (of trees, etc., after French séculaire)…

(un-, prefix1 affix 2.)

(un-, prefix1 affix 1.)

Recurring or operative at every moment.

That stands or remains in an unchanged state or condition. Obsolete.

Surviving, enduring.

Of actions, conditions, processes, etc.: Continuing without intermission or cessation, or only with such intermissions as do not interrupt…

Extensive in area or in time. rare.

lasting, permanent, enduring continuously.

Lasting, permanent; continuous.

That lives long, that endures; lasting.

Of a spring, stream, water supply, etc.: lasting or continuing throughout the year or through all seasons of the year.

= longevous, adj.

Having continuous sequence in time. Obsolete.

Of fire, light, etc.: not extinguished. Frequently figurative and in figurative contexts.

= livelong, adj. 1. Now rare.

Recurring or operative at every moment. Obsolete.

Persistent, lasting.

Firmly established, enduring, lasting. rare.

Continuous, continuing to exist; enduring, lasting; chronic.

Not passing; esp. (of time or things bound or measured by time) not passing away; enduring.

Enduring; timeless.

hyperbolically. Esp. of a period of time: seeming to last as long as a year.

attributive and in other combinations, as teak forest, teak log, teak-oil, teak ship, teak timber, teak-tree, teak-wood; teak-built (in quot. 1847…

Of great length, long.

That lasts for, relates to, or involves a relatively long period of time; maturing or becoming effective only after a long period.

Usually hyphenated. Designating the transport of goods, passengers, etc., over a long distance; relating to or involved in such transport. Also…

Long-lasting, persistent.

week-to-week: (attributive) (originally) arranged by the week; calculated in terms of a week; (now more usually) continuous for successive weeks…

Enduring throughout a process or action, or for a long period of time.

Of or relating to a period of time extending far into the future; long-term.

Somewhat long; fairly long.

That requires, takes up, or lasts for a long time.

Taken or considered in the long run; = long-term, adj.

Of a product: able to continue working for longer than others of the same kind.