(a) Physiology and Pathology (cf. trigger area n. above); (b) U.S. a price level at which price controls are imposed or re-imposed.

a lower price level for a security or commodity below which prices do not ordinarily fall; cf. resistance level n. at resistance, n. compounds 4.

An upper limit (to quantity, prices, expenditure, etc.); a maximum. Also attributive. Cf. floor, n.1 1c.

Of prices, expenditure, etc.: = ceiling, n. 6d. Cf. earlier roofless, adj. 4.

In extended sense: The base of any cavity; the bottom of a lake, sea, etc. Also figurative: a minimum, esp. of prices or wages. Cf. ceiling, n. 6d.

(a) a level that triggers support of prices, etc., esp. in agricultural produce; (b) = support level n.