What's the difference between i.e. and e.g.?
early 14c., "harsh or severe treatment," from Old French duresse, from Latin duritia "hardness," from durus "hard" (see endure). The Old French suffix -esse is from Latin -itia, added to adjectives to form nouns of quality (cf. riches, largesse). Sense of "coercion, compulsion" is from 1590s.