This is the 184th most frequent Persian word.
اثر
"Effect," "work," or "trace."
Here, 'اثر' highlights the 'impact' or 'lasting impression' left as a consequence of the discovery.
از نظر علمی، این کشف تاثیر زیادی بر علم داشت و اثر ماندگاری بر جای گذاشت.
From a scientific perspective, this discovery had a significant impact on science and left a lasting effect.
Here, 'اثر' refers to the 'effect' or 'result' of effort and perseverance, indicating a causal relationship.
اثر تلاش و پشتکار، موفقیت خواهد بود.
The effect of effort and perseverance will be success.
In this sentence, 'اثر' is used to denote 'work', specifically an artistic creation or opus.