upsetter Definition

upset
verb

1. To disturb or distress someone emotionally.

Thesaurus: disturb, trouble, agitate, fluster, perturb, bother, distress, grieve, disconcert, unnerve, dismay, shake, ruffle.
2. To ruin or spoil (eg plans, etc).
3. To disturb the proper balance or function of (a person's stomach or digestion).
4. To disturb something's normal balance or stability.
tr & intr
5. To knock something over or overturn.

Thesaurus: overturn, topple, tip over, upend, invert, capsize; Antonym: stand, erect, elevate.
6. To defeat or overthrow (an opponent), especially unexpectedly.

noun

1. A disturbance or disorder, eg of plans, the digestion, etc.

Thesaurus: defeat, subversion, upheaval, overthrow, reversal, disturbance.
2. An unexpected result or outcome, eg of a contest.

adj

1. Emotionally distressed, angry or offended, etc.

Thesaurus: pained, distressed, troubled, grieved, worried, disconcerted, bothered, dismayed.
2. Disturbed.

Example: an upset stomach

Derivative: upsetter
noun

Derivative: upsetting
adj

Derivative: upsettingly
adverb