a combining form meaning “one and a half,” used in the formation of compound words: sesquicentennial.

Origin of sesqui-

< Latin sēsqui- < *sēm(i)sque, equivalent to sēmis half-unit, semis + -que and (cognate with Greek té, Sanskrit ca, Gothic -uh) Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for sesqui-



indicating one and a halfsesquicentennial
(in a chemical compound) indicating a ratio of two to threesesquioxide

Word Origin for sesqui-

from Latin, contraction of semi- + as as ² + -que and
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