coalescence (n.)

A term used in LINGUISTICS, especially in HISTORICAL studies, to refer to the coming together of linguistic UNITS which were originally distinguishable. ALLOphones of a PHONEME may coalesce, as may different phonemes and different MORPHEMES. Many CASES of Modern English , for example, are the result of coalescence of /z/ and /j/, e.g. occasion, measure; in WORDS like formation, one could analyze the AFFIX as a coalescence of the morphemes -ate + -tion. Analogous terms include SYNCRETISM, MERGER, FUSION and NEUTRALIZATION.