semi

The prefix 'semi' is a direct borrowing from the Latin word 'sēmi-', meaning 'half'. This Latin term is itself a reduced form of the Proto-Indo-European root sēmi-, which carried the same meaning. In English, it has been a productive prefix since at least the 15th century, used literally to denote something that is exactly half (as in 'semicircle') and figuratively to suggest something that is partial or incomplete (as in 'semi-conscious'). Its logic is straightforward, consistently imparting a sense of being halfway between two states or of diminished completeness.

Structure: semi (half) semi (Latin origin, meaning 'half'). It functions as a prefix in English.