milkyoudaoicibaDictYouDict[milk 词源字典]
milk: [OE] Far back into prehistory, milk traces its ancestry to an Indo-European base *melg-, which denoted ‘wiping’ or ‘stroking’. The way of obtaining milk from animals is to pull one’s hand down their teats, and so *melg- came in due course to be used for ‘milk’. It passed into Germanic as *melk-, which formed the basis of the noun *meluks, and this over the centuries has become German milch, Dutch and Danish melk, Swedish mjölk, and English milk.

The now virtually obsolete adjective milch ‘giving milk’ [OE] (as in milch cow) goes back to a Germanic derivative of *meluks. Another derivative of Indo-European *melgwas the Latin verb mulgēre ‘milk’, which has given English emulsion and promulgate.
=> emulsion, promulgate[milk etymology, milk origin, 英语词源]
weight (n.)youdaoicibaDictYouDict
Old English gewiht "weighing, weight, downward force of a body, heaviness," from Proto-Germanic *wihti- (cognates: Old Norse vætt, Danish vegt, Old Frisian wicht, Middle Dutch gewicht, German Gewicht), from *weg- (see weigh).

Figurative sense of "burden" is late 14c. To lose weight "get thinner" is recorded from 1961. Weight Watcher as a trademark name dates from 1960. To pull one's weight (1921) is from rowing. To throw (one's) weight around figuratively is by 1922. Weight-training is from 1945. Weight-lifting is from 1885; weight-lifter (human) from 1893.