subsesqui- Meaning, Definition & Usage

Sub*ses"qui-
Etymology
Pref. sub- + sesqui-.
Definitions
  1. (Chem.) A prefix (also used adjectively) denoting the combination of constituents (especially electro-negative and electro-positive bodies) in the proportion of two to three; as, a subsesqui acetate, i. e., a salt having two equivalents of acetic acid to three of the base.

Webster 1913