What is a contraction of syllables by suppressing some vowel or diphthong at the end of a word, before another vowel or diphthong; as, th' army, for the army. [Written also synaloepha.] called?

synalepha — A contraction of syllables by suppressing some vowel or diphthong at the end of a word, before another vowel or diphthong; as, th' army, for the army. [Written also synaloepha.]. (Webster's 1913.)

Sources