Car
late Middle English (in the general sense ‘wheeled vehicle’): from Old Northern French carre, based on Latin carrum, carrus, of Celtic origin.
wiktionary
Middle English carre, borrowed from Anglo-Norman carre, from Old Northern French (compare Old French char), from Latin carra, neuter plural of carrus(“four-wheeled baggage wagon”), from Gaulish *karros, from Proto-Celtic *karros(“wagon”).
Etymology unclear, but probably from Proto-Germanic *karzijaną(“to turn”), from Proto-Indo-European *gers-(“to bend, turn”). Compare cair(“to turn, go”), char(“to turn”), Dutch keren(“to turn”), German Kehre(“turn, bend”).
Shakespeare had something of a fondness for verbalizing nouns, and sometimes even substantivizing verbs. However, anything other than a "turn" does not seem to make any sense within the broader context of the cited Sonnet.
Acronym of contents of the address part of register number. Note that it was based on original hardware and has no meaning today.
etymonline
car (n.)
c. 1300, "wheeled vehicle," from Anglo-French carre, Old North French carre, from Vulgar Latin *carra, related to Latin carrum, carrus (plural carra), originally "two-wheeled Celtic war chariot," from Gaulish karros, a Celtic word (compare Old Irish and Welsh carr "cart, wagon," Breton karr "chariot"), from PIE *krsos, from root *kers- "to run."
"From 16th to 19th c. chiefly poetic, with associations of dignity, solemnity, or splendour ..." [OED]. Used in U.S. by 1826 of railway freight carriages and of passenger coaches on a railway by 1830; by 1862 of streetcars or tramway cars. Extension to "automobile" is by 1896, but from 1831 to the first decade of 20c. the cars meant "railroad train." Car bomb first attested 1972, in reference to Northern Ireland. The Latin word also is the source of Italian and Spanish carro, French char.
