(colloquial) The exact likeness (of someone).

(informal) Ellipsis of in the pink of health. / (informal) Nude, naked.

(colloquial) To begin eating. / (colloquial) To engage in a burst of hard work. / (military, also figuratively in sports) To dig trenches to resist an enemy attack.

(music) Having the correct musical pitch. / (figuratively, usually with "with") In an understanding relationship (with something or someone).

(simile, colloquial) Very cosy and comfortable.

(physics) The ratio of the speed of light in air or vacuum to that in another medium.

In a state of suspension; nebulous and unfulfilled. / (law) In abeyance.

(biochemistry) A unit comprising two or more iron atoms and bridging sulfur ligands in an iron-sulfur protein.

(Britain) Alternative spelling of iron-sulfur cluster

(biochemistry) any protein in which iron is coordinated with cysteine sulfur and sometimes also with inorganic sulfur; they have electron transfer and enzymatic function