Compare German bänkling "bastard; child begotten on a bench" (and not in a marriage bed), the source of English bantling (1590s) "brat, small child." Bastard was not always regarded as a stigma; the Conqueror is referred to in state documents as "William the Bastard." Figurative sense of "something not pure or genuine" is late 14c. Use as a generic vulgar term of abuse for a man is attested from 1830. Among the "bastard" words in Halliwell-Phillipps' "Dictionary of Archaic and Provincial Words" are avetrol, chance-bairn, by-blow, harecoppe, horcop, and gimbo ("a bastard's bastard").
As an adjective from late 14c. It is used of things spurious or not genuine, having the appearance of being genuine, of abnormal or irregular shape or size, and of mongrels or mixed breeds.
1640s, "allied by blood, connected or related by birth, of the same parentage, descended from a common ancestor," from Latin cognatus "of common descent" (source also of Spanish cognado, Italian cognato), from assimilated form of com "together" (see co-) + gnatus, past participle of gnasci, older form of nasci "to be born" (from PIE root *gene- "give birth, beget").
Of things, "related in origin, traceable to the same source," by 1640s; specifically of words, "coming from the same root or original word but showing differences due to subsequent separate phonetic development," by 1782; of languages, "from the same original language," by 1799. French, Spanish, and Italian are cognate languages (all essentially descended from Latin) but are not cognate with Latin. English cognate, Spanish cognado and Italian cognato are cognate words from Latin cognatus. English brother, Sanskrit bhrtr-, Greek phratr, Latin frater, Russian brat are cognate words from the PIE root *bhrater. Words that are cognates are more like cousins than siblings; they develop in different languages.
Related: Cognatic; cognation (late 14c. in English as "blood-relationship, kinship"); cognateness. As a noun, "one connected to another by ties of kinship," from 1754.
Proto-Indo-European root meaning "to carry," also "to bear children."
It forms all or part of: Aberdeen; amphora; anaphora; aquifer; auriferous; bairn; barrow (n.1) "frame for carrying a load;" bear (v.); bearing; Berenice; bier; birth; bring; burden (n.1) "a load;" carboniferous; Christopher; chromatophore; circumference; confer; conference; conifer; cumber; cumbersome; defer (v.2) "yield;" differ; difference; differentiate; efferent; esophagus; euphoria; ferret; fertile; Foraminifera; forbear (v.); fossiliferous; furtive; indifferent; infer; Inverness; Lucifer; metaphor; odoriferous; offer; opprobrium; overbear; paraphernalia; periphery; pestiferous; pheromone; phoresy; phosphorus; Porifera; prefer; proffer; proliferation; pyrophoric; refer; reference; semaphore; somniferous; splendiferous; suffer; transfer; vociferate; vociferous.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit bharati "he carries, brings," bhrtih "a bringing, maintenance;" Avestan baraiti "carries;" Old Persian barantiy "they carry;" Armenian berem "I carry;" Greek pherein "to carry," pherne "dowry;" Latin ferre "to bear, carry," fors (genitive fortis) "chance, luck," perhaps fur "a thief;" Old Irish beru/berim "I catch, I bring forth," beirid "to carry;" Old Welsh beryt "to flow;" Gothic bairan "to carry;" Old English and Old High German beran, Old Norse bera "barrow;" Old Church Slavonic birati "to take;" Russian brat' "to take," bremya "a burden," beremennaya "pregnant."