adjective
Definition 1
Make tense, i.e. (of cord, membrane, nerve, figuratively of mind, emotion) stretched tight, strained to stiffness.
Source: Concise Oxford Dictionary
Context: She is brought to the point of nausea by "his tongue, tensed and strong, pushing past her teeth... It was the hard tapering tip of this alien muscle, quiveringly alive, that repelled her".
Source: Financial Times 20/04/2007 (review by Mark Ford of "On Chesil Beach" by Ian McKewan