Where does “coastline” come from?

Coastline comes from English coast, from Old French coste meaning rib or side, from Latin costa meaning rib, ultimately from Proto-Indo-European līno-.

coastline (English): The shape, outline, or boundary of a coast

Definitions

  1. The shape, outline, or boundary of a coast

Ancestry of “coastline”, step by step

coastline traces back through two separate lines of ancestry.

via English line

StepLanguageWordMeaning
1EnglishlineA path through two or more points (compare ‘segment’); a continuous mark, including as made by a pen; any path, curved or straight
2Middle Englishlinerope, cord; line, rule, ruler, measure; rule,...
3Old Englishlīneline, rope, cord; line, cable, rope, hawser,...
4Proto-West Germanic*līnāline, chord, rope, string
5Proto-Germaniclīnǭthat which is made of flax; line, chord, rope,...
6Proto-Germaniclīnąflax
7Proto-Indo-Europeanlīno-flax

via English coast

StepLanguageWordMeaning
1EnglishcoastThe edge of the land where it meets an ocean,...
2Middle Englishcoste
3Old Frenchcostéside
4Latincostātusribbed
5Latincostaa rib; a side, a wall
6Proto-Indo-Europeankost-

Words derived from “coastline

Every word from Proto-Indo-European līno-
coastline — Etymology, Origin & Word History | Etymology Explorer