Most inclined to give orders and control others; the superlative form of bossy.
From 'boss' plus superlative suffix '-iest'. This follows the standard English pattern for turning adjectives into their most extreme form.
English has two ways to show the strongest form of adjectives—'bossy' becomes 'bossiest' but 'controlling' becomes 'most controlling.' We tend to use the '-est' form for shorter adjectives and 'most' for longer ones, a pattern linguists still don't fully understand.
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