Synaloepha (Greek, ‘melting together’) is the contraction of two or more syllables which are adjacent across a word boundary. The most typical case is crasis. Synaloepha may, however, work across a syllable boundary not necessarily flanked by vowels.

Examples:

Other than crasis: Take't: 'tis yours. What is't? (Shakespeare, Coriolanus I.9.80)
German für das → für's;
Latin noxam et /'noksãet/ → /'nokset/ (Verg. Aen. I, 41)