味 appears in many compounds: 味道 (taste/flavor), 气味 (smell/odor), 趣味 (interest/fun), 意味 (meaning/significance). As a suffix it creates flavors: 酸味 (sour), 甜味 (sweet).
grammar
味 is also a measure word for Chinese medicine prescriptions: 一味药 (one ingredient of herbal medicine).
Left mouth - the indexing radical. Anchors 味 in what the mouth perceives: taste. From physical taste came smell, flavor, and abstractly nuance or feel of something. Same mouth-perception family: 吃 (eat), 喝 (drink), 吸 (inhale).
Right 未 supplies the sound exactly (wèi) and adds a fitting semantic flavor: 未 means subtle or not-yet-fully-formed, and taste is exactly that - a subtle quality dissolving on the tongue. Same phonetic family: 妹 (younger sister), 昧 (obscure), 寐 (sleep).
