Where does “flatline” come from?

flatline (English) comes from English flat, from Scots flet, from Middle English flet, from Old English flet, from Proto-Germanic flatją, from Proto-Germanic flataz, from Proto-Indo-European plÁt-.

flatline (English): An unchanging state, as indicated in a graph of a...

Definitions

  1. An unchanging state, as indicated in a graph of a...

Ancestry of “flatline”, step by step

flatline traces back through two separate lines of ancestry.

via English flat

StepLanguageWordMeaning
1EnglishflatHaving no variations in height; Without...
2Scotsfletinner part of a house
3Middle Englishfletthe floor, ground; a dwelling, habitation, house,...
4Old Englishfletthe floor, ground; a dwelling, habitation, house,...
5Proto-Germanicflatjąa level surface; level ground; the floor of a...
6Proto-Germanicflatazflat
7Proto-Indo-EuropeanplÁt-

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

Words derived from “flatline

Every word from Proto-Indo-European plÁt-Every word from Proto-Germanic flatazEvery word from Proto-Germanic flatją