blow-off

The compound noun 'blow-off' is a transparent combination of the verb 'blow' and the adverbial particle 'off', following a common Germanic pattern for forming phrasal nouns. Its literal, mechanical sense of "a blowing off" (as of steam) directly applies the core meaning of expelling something away. This concrete image was then semantically extended in informal usage to describe an event that is figuratively "blown away" or dismissed as trivial, or a final party that serves to "blow off" pent-up energy or mark a conclusion. The logic of the word consistently hinges on the concept of forceful expulsion or release, whether physical or metaphorical.

Structure: blow (to expel air) + off (away) 'Blow' originates from Old English blāwan, meaning "to move air, to puff," from Proto-Germanic blǣ-, and ultimately from the Proto-Indo-European root bhlē- ("to swell, blow"). Its functional role is the core action. 'Off' originates from Old English of, meaning "away, away from," from Proto-Germanic af, and ultimately from the Proto-Indo-European root apo- ("off, away"). Its functional role is a particle indicating direction or separation.