Where does “red tide” come from?

red tide (English) comes from English Red, from English rede, from Middle English reden, from Old English rǣdan, from Proto-West Germanic rādan, from Proto-Germanic rēdaną, from Proto-Indo-European Hreh₁dʰ-, from Proto-Indo-European h₂reh₁- — to fit, to fix, to put together.

red tide (English): An algal bloom of sufficient quantity to cause...

Definitions

  1. An algal bloom of sufficient quantity to cause...

Ancestry of “red tide”, step by step

red tide traces back through two separate lines of ancestry.

via English Red

StepLanguageWordMeaning
1EnglishRedA Communist; A supporter of a sports team who...
2EnglishredeHelp, advice, counsel; Decision, a plan; To...
3Middle Englishredento counsel, advise; to study; to read
4Old Englishrǣdanto read, interpret; to counsel, advise; plot,...
5Proto-West Germanicrādanto advise, counsel, help; to devise, decide,...
6Proto-Germanicrēdanąto decide, advise
7Proto-Indo-EuropeanHreh₁dʰ-to think; to arrange; to succeed, accomplish
8Proto-Indo-Europeanh₂reh₁-to think, reason; to arrange
9Proto-Indo-Europeanh₂er-to fit, to fix, to put together

via English tide

StepLanguageWordMeaning
1EnglishtideThe periodic change of the sea level,...
2Middle EnglishtydeA time (period), season
3Old Englishtīdtime, period, season; period, season, time;...
4Proto-Germanictīdiztime; period, interval
5Proto-Indo-Europeandéh₂itisinterval, period of time
6Proto-Indo-Europeandeh₂y-to share, divide
7Proto-Indo-Europeandeh₂-to share, divide
Every word from Proto-Indo-European h₂er-Every word from Proto-Indo-European h₂reh₁-Every word from Proto-Indo-European Hreh₁dʰ-