So as to avoid observation or notice; unobtrusively.

by stale = by stealth.

Not openly or publicly; secretly, in secret; stealthily, craftily; discreetly, circumspectly. In early use also: †by oneself, alone (obsolete).

†(a) Cleverly, skilfully, dexterously; wisely. Obsolete. (b) Cunningly, artfully; covertly, secretly, stealthily, quietly.

In a thievish or thief-like manner; by stealth; stealthily, furtively.

stealthily, furtively, so as to elude observation.

by stealth:†(a) (with reference to taking or appropriating) by an act of theft; secretly and without right or permission; also in wider sense, with…

? Misused (through association with stale, n.1) for: Clandestinely, secretly.

By stealth: = theftly, adv.

By stealth, furtively.

In a theftuous manner; by or as by theft; stealthily, secretly.

under veil: surreptitiously, covertly. Obsolete. rare.

In a thievish manner; as a thief; furtively, by stealth.

by theft, stealthily, furtively, by secret craft. Obsolete. rare.

In a quiet manner (in various senses of the adjective); peacefully, meekly; with little or no noise, fuss, or disturbance; surreptitiously…

The action of seizing or taking away by stealth; stealing, theft. by surreption: by stealth, stealthily (cf. surreption, n.2). Now rare or Obsolete.

Secretly, clandestinely; ‘in hugger-mugger’.

Concealment, secrecy; esp. in in hugger-mugger: in secret, secretly, clandestinely. Formerly in ordinary literary use, now archaic or informal.

In a secret, covert, or stealthy manner; by secret means; quietly or unobtrusively.

In an insidious manner; by secret plotting or artifice; in a subtle or underhand way; slyly, craftily, treacherously, deceitfully.

In a creeping manner. literal and figurative.

surreptitiously.

In an underhand or secret manner; clandestinely; not openly or honestly. (Opposed to above-board.)

In a filching manner; stealthily, surreptitiously.

In a sneaking manner; not openly or boldly.

figurative. In or into danger or difficulty; esp. with reference to financial difficulty (cf. above water at water, n. phrases 1a(b)).

In a slippery manner. Chiefly figurative.

In the manner of a thief.

In a clandestine manner; secretly, privately: usually in bad sense.

In a surreptitious manner. In an underhand way; secretly and without authority; clandestinely, by stealth, ‘on the sly’.

= thievishly, adv.

In a clandestine manner; secretly, privately.

By stealth; secretly.

In a stealthy manner.

stealthily.

on (upon, under,or by) the sly, in a secret, clandestine, or covert manner; without publicity or openness; secretly, covertly, stealthily.

roundabout, indirect.

= underhand, adv. 3.

Cant. The act or practice of stealing in unperceived in order to rob; a robbery effected in this manner. Usually in upon the sneak. Also more…

Meanly, despicably. Also, in a sneaking or stealthy manner.

With prepositions. behind the back of: (emphatic for) behind; in the absence of, out of the sight, hearing, or knowledge of; behind backs…

In addition to a main activity, course of action, etc.; spec. in a clandestine or surreptitious way; secretly; illicitly.

under the counter, used with reference to illegal or clandestine transactions.

figurative. Into hiding or surreptitious activity, esp. in to go underground: applied chiefly to political organizations and their representatives…

In a clandestine or underhand way; secretly; illicitly. Frequently attributive (usually hyphenated): secret, hidden, done in a clandestine or…

In a devious or surreptitious manner.