Plural of left; refers to multiple instances of the left side, or in politics, leftist groups or ideologies.
From Old English 'lyft' meaning 'weak' or 'feeble,' because left-handed people were historically seen as clumsy. The political meaning developed in late 1700s France from seating arrangements.
The terms 'left' and 'right' in politics come from where people literally sat in the French assembly—the radicals sat on the left and conservatives on the right, and the geography became ideology!
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