erratic
adj.adj. moving or behaving in a way that is not regular or certain. You use this to describe something that changes suddenly and is hard to predict.
adj. characterised by lack of consistency, regularity, or uniformity. Often describes movement, behaviour, or data patterns that deviate from expected paths.
The car's erratic movements made the other drivers nervous.
The stock market has shown erratic behavior lately, with prices jumping up and down for no clear reason.
Despite the athlete's undeniable talent, his erratic training schedule and unpredictable mood swings eventually led the coach to remove him from the starting lineup.
From Middle English erratik, erratyk, from Latin errāticus; compare Old French erratique.
Often used to describe physical motion, weather patterns, or human behavior; frequently follows linking verbs like 'become' or 'remain'.