to get irritated; to get upset; to get annoyed; to lose one's temper; to respond to an irritating stimulus with some reaction
Building blocks
ärri- - from the word ärev (anxious or agitated)
-tu- - reflexive (the action is being done to oneself)
-ma - infinitive ending
So, "ärrituma" means "to become irritated" or "to get irritated," reflecting the idea of becoming agitated or anxious, derived from the root word "ärev."
There is another very similar word; here is the comparison:
Ärrituma: "to become irritated" or "to get irritated." It describes a process where the subject experiences irritation or agitation, typically as a response to some external stimulus.
Example: Ma ärritusin tema sõnadest. (I got irritated by his words.)
Ärritama: "to irritate" or "to provoke." It describes an action where the subject causes irritation or agitation in someone or something else.
Example: Tema sõnad ärritasid mind. (His words irritated me.)
How to use it
Psychological Reaction (Getting Nervous or Angry):
Ma ärritusin, kui ta mind süüdistama hakkas.
Translation: I got irritated when he started blaming me.
Physical Reaction (Tissues/Organs Responding to an Irritant):
Mu nahk ärritub kergesti
Translation: My skin becomes irritated easily.
Examples
Erakonna juhatuse liikmed olid sellisest jutust silmanähtavalt ärritunud
Literally: “Party board members were such-from talk-from visibly irritated”
Idiomatically: “The members of the party board were visibly irritated by such talk”
Erakonna - Noun - Genitive Sg, "Party"
juhatuse - Noun - Genitive Sg, "board"
liikmed - Noun - Nominative Pl, "members"
olid (ärritunud) - Verb - 3P Past Perfect Pl, "were (irritated)"
sellisest - Pronoun - Elative Sg, "from such"
jutust - Noun - Elative Sg, "from the talk"
silmanähtavalt - Adjective - Ablative Sg, "visibly"
(olid) ärritunud - Verb - 3P Past Perfect Pl, "(were) irritated"