1. n.1 a ridge of rock or coral etc. at or near the surface of the sea.
2 a a lode of ore. b the bedrock surrounding this.
Etymology: earlier riff(e) f. MDu., MLG rif, ref, f. ON rif RIB 2. n. & v. Naut.
--n. each of several strips across a sail, for taking it in or rolling it up to reduce the surface area in a high wind.
--v.tr.
1. take in a reef or reefs of (a sail).
2 shorten (a topmast or a bowsprit).
Phrases and idioms:
reefing-jacket a thick close-fitting double-breasted jacket. reef-knot a double knot made symmetrically to hold securely and cast off easily. reef-point each of several short pieces of rope attached to a sail to secure it when reefed.
Etymology: ME riff, refe f. Du. reef, rif f. ON rif RIB, in the same sense: cf. REEF(1)