laughing gas noun

Nitrous oxide, which may excite laughter when breathed

laughing gear noun (slang, orig Aust)

The mouth

laughing hyena noun

The spotted hyena (Crocuta crocuta; see under hyena)

laughing jackass noun

The kookaburra

laughing stock noun

An object of ridicule

laugh track or laughter track noun

Recorded laughter edited into the soundtrack of a TV comedy programme

be laughing (informal)

1. To have no (further) problems, worries, etc
2. To be in a favourable or advantageous position

don't make me laugh (informal)

An expression of scornful disbelief

have the last laugh

1. To triumph finally after one or more setbacks or defeats
2. To have one's actions, etc finally vindicated after being scorned

have the laugh of

To get the better of

laugh in someone's face

To scorn or mock a person openly

laugh off

To treat (injuries, etc) as of no importance

laugh on the other side of one's face or (rare) on the wrong side of one's mouth

To be made to feel disappointment or sorrow, esp after boasting, etc

laugh someone out of court

To prevent someone getting a hearing by ridicule

laugh to scorn

To deride or jeer at

laugh up one's sleeve or (rare) in one's sleeve

To laugh inwardly

no laughing matter

A very serious matter

nitre or (US) niter /nīˈtər/

1. Potassium nitrate or saltpetre (cubic nitre is sodium nitrate, or Chile saltpetre)
2. Sodium carbonate (obsolete)
3. A supposed nitrous substance in the air, etc (obsolete)

niˈtrate noun

1. A salt or ester of nitric acid
2. Natural (potassium or sodium) or synthetic (calcium) nitrate, a fertilizer

1. To treat with nitric acid or a nitrate
2. To convert into a nitrate or nitro-compound

nitratine /nīˈtrə-tin/ noun

Sodium nitrate as a mineral

nitrāˈtion noun

niˈtric adjective

Of or containing nitrogen

niˈtride noun

A compound of nitrogen with a metal

1. To turn into a nitride
2. To harden the surface of by heating in ammonia gas

niˈtriding noun

nitrificāˈtion noun

1. Treatment with nitric acid
2. Conversion into nitrates, esp by bacteria through the intermediate condition of nitrites

niˈtrify transitive verb and intransitive verb

To subject to or suffer nitrification

niˈtrile /-tril, -trēl or -trīl/ noun

Any of a group of organic cyanides (general formula RC≡N)

niˈtrite noun

A salt or ester of nitrous acid

niˈtrous adjective

Of, like, derived from or containing nitrogen

niˈtry adjective (obsolete)

Applied to the air, as supposed to contain nitre

niˈtryl noun

Nitroxyl (see under nitro-)

nitric acid noun

A colourless or pale yellow corrosive liquid (HNO₃), used in the production of fertilizers and explosives

nitric anhydride noun

A white crystalline solid (N₂O₅) which dissolves in water to produce nitric acid

nitric oxide noun

A colourless toxic gas (NO) produced by cellular metabolism and as an intermediate in the manufacture of nitric acid

nitrous acid noun

A pale-blue unstable solution (HNO₂) obtained by the action of an acid on nitrites

nitrous anhydride noun

A pale-blue liquid (N₂O₃) that reacts with water to form nitrous acid

nitrous bacteria plural noun

A type of nitrobacteria (qv)

nitrous oxide noun

A colourless gas (N₂O) with a sweetish odour and taste, used as an anaesthetic, esp in dentistry (also laughing gas)