verb
1.
Synonyms: overturn 1, knock over, overset, overthrow, tip (over), topple, turn over
Related Word: invert, reverse; bend, curve, turn
2.
Synonyms: discompose 1, agitate, bother, discombobulate, disquiet, disturb, flurry, fluster, perturb, unhinge
Related Word: bewilder, confound, distract; unman, unnerve
Idioms: rock the boat
3.
Synonyms: trouble 1, ail, cark, distress, worry
4.
Synonyms: disorder 1, derange, disarrange, disarray, jumble, mix up, muddle, rummage, tumble, unsettle
5.
to disturb the normal functioning especially of body or mind
her stomach was badly upset by too many sweets
Synonyms: derange, disorder, sicken, turn, unhinge, unsettle
Related Word: afflict, indispose, lay up; ail, suffer; debilitate, incapacitate, invalid