/ek thlip"sis/ , n. , pl. ecthlipses /-seez/ .
loss of a consonant, esp., in Latin, loss of a final m before a word beginning with a vowel or h.
[ 1650-60; ékthlipsis, equiv. to ekthlíb ( ein ) to squeeze out ( ek- EC- + thlíbein, var. of PHLÍBEIN to squeeze) + -sis -SIS ]