biasyoudaoicibaDictYouDict[bias 词源字典]
bias: [16] English acquired bias from Old French biais, but its previous history is uncertain. It probably came via Old Provençal, but where from? Speculations include Latin bifacem ‘looking two ways’, from bi- ‘two’ and faciēs ‘face’, and Greek epikársios ‘oblique’. When the word first entered English it meant simply ‘oblique line’, but by the end of the 16th century it was being applied more specifically to the game of bowls, in the sense of the ‘bowl’s curved path’, and also the ‘unequal weighting given to the bowl in order to achieve such a path’.

The modern figurative senses ‘inclination’ and ‘prejudice’ derive from this.

[bias etymology, bias origin, 英语词源]
plumbing (n.)youdaoicibaDictYouDict
mid-15c., "the weighting of a fishing line," verbal noun from plumb (v.). Specific meaning "water and drainage pipes" is recorded by 1875, American English.
THE apparatus by which the water from a reservoir is carried about over a building and delivered at points convenient for use, is called by the general name of plumbing. The word "plumbing" means lead-work; and it is used to signify this water apparatus of a house because the pipes of which it largely consists are usually made of lead. [Edward Abbott, "Long Look House: A Book for Boys and Girls," Boston, 1877]
Alternative plumbery also is mid-15c. Slang meaning "a person's reproductive organs" attested by 1975.
weight (v.)youdaoicibaDictYouDict
"to load with weight," 1747 (figuratively, of the mind, from 1640s), from weight (n.). Of horses in a handicap race, 1846. Sense in statistics is recorded from 1901. Related: Weighted; weighting.