•bother, what a bore, phew! · oof!, yikes; an expression of surprise, exhaustion, and often frustration · Expression of empathy with unpleasant or undesirable circumstances.
köken: Compare vù (as in sưng vù). For some other pairs of plain/lenited vs. aspirated initial forms, compare gảy vs. khảy, quấy vs. khuấy, cứa vs. khứa, bứt vs. phứt, bỏng vs. phỏng.