sheet anchor Meaning, Definition & Usage

  1. noun spare anchor for use in emergency
    waist anchor.

WordNet

Sheet" an"chor
Etymology
OE. scheten to shoot, AS. sceótan; cf. OE. shoot anchor. See Shoot, v. t.
Definitions
  1. (Naut.) A large anchor stowed on shores outside the waist of a vessel; -- called also waist anchor. See the Note under Anchor.
  2. Anything regarded as a sure support or dependence in danger; the best hope or refuge.

Webster 1913