Old English werian "to clothe, put on," from Proto-Germanic *wazjanan (cf. Old Norse verja, Old High German werian, Gothic gawasjan "to clothe"), from PIE *wes- "to clothe" (cf. Sanskrit vaste "he puts on," vasanam "garment;" Avestan vah-; Greek esthes "clothing," hennymi "to clothe," eima "garment;" Latin vestire "to clothe;" Welsh gwisgo, Breton gwiska; Old English wæstling "sheet, blanket;" Hittite washshush "garments," washanzi "they dress").
The Germanic forms "were homonyms of the vb. for 'prevent, ward off, protect' (Goth. warjan, O.E. werian, etc.), and this was prob. a factor in their early displacement in most of the Gmc. languages" [Buck]. Shifted from a weak verb (past tense and past participle wered) to a strong one (past tense wore, past participle worn) in 14c. on analogy of rhyming strong verbs such as bear and tear.
Secondary sense of "use up, gradually damage" (late 13c.) is from effect of continued use on clothes. To be the worse for wear is attested from 1782; noun phrase wear and tear is first recorded 1660s.
"action of wearing" (clothes), mid-15c., from wear (v.). Meaning "what one wears" is 1570s. To be the worse for wear is attested from 1782; noun phrase wear and tear is first recorded 1660s, implying the sense "process of being degraded by use."
the removal of material from a solid surface as a result of mechanical action exerted by another solid. Wear chiefly occurs as a progressive loss of material resulting from the mechanical interaction of two sliding surfaces under load. Wear is such a universal phenomenon that rarely do two solid bodies slide over each other or even touch each other without a measurable material transfer or material loss. Thus, coins become worn as a result of continued contact with fabrics and human fingers; pencils become worn after sliding over paper; and rails become worn as a result of the continued rolling of train wheels over them. Only living things (such as bone joints) are in some sense immune to the permanent damage caused by wear, since they have the property of regrowth and healing