In a way that causes feelings of pity or sadness; in a manner that is weak or inadequate.
From 'pathetic' (from Greek 'pathos' meaning suffering or feeling) plus the adverb suffix '-ly'. The word evolved from describing things that evoke strong emotions to meaning pitifully weak.
The Greek root 'pathos' gave us not just 'pathetic' but also 'empathy' and 'sympathy'—all about feeling and suffering. It's wild how one ancient word branched into so many ways we talk about emotion.
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