Swimming. the upward and downward movement of the legs, as in the crawl.
11.
BritishSlang. a party, usually with drinks.
Verb phrase
12.
thrash out/over, to talk over thoroughly and vigorously in order to reach a decision, conclusion, or understanding; discuss exhaustively. Also, thresh out/over.
Origin: before 900; Middle English thrasshen, variant of thresshen to thresh
1588, "to separate grains from wheat, etc., by beating," dial. variant of threshen (see thresh). Sense of "beat (someone) with (or as if with) a flail" is first recorded 1606. Meaning "to make wild movements like those of a flail or whip" is attested from 1846. Type of fast