Sad means feeling bad and close to tears. Feel sad, a sad story, sad about it.
It is the plain everyday word, and unhappy, miserable and heartbroken run up the scale from it. Of a fact it means regrettable: the sad truth, sadly. In British informal use, sad also means pathetic and dull — a sad little man, that is sad — which is a serious insult and quite separate. Note sadly, which as a sentence adverb means unfortunately; and that sad once meant full, which survives in nothing at all.
1adjectivesadFeeling bad and close to tears.
“She felt sad when her best friend moved to another city.”
synonyms: unhappy, sorrowful
2adjectiveregrettableRegrettable.
“The sad fact is that nobody reads the instructions.”
Too few real examples of this word to estimate which sense is commonest.
sad is a state of unhappiness.
Also accepted in games: unhappy
Old English saed meant sated or weary — the same root as satisfy and satiate. Sad meant having had enough, then serious, then sorrowful, which is a slide of about nine hundred years.
Proto-Indo-European
*seh₂- — to satiate, satisfy
Proto-Germanic
*sadaz — sated, satisfied
Proto-West Germanic
*sad
Old English
sæd — satisfied, full, sated, unable to handle more, weary
Middle English
sad
English, today
sad
From Middle English sad, from Old English sæd (“satisfied, full, sated, unable to handle more, weary”), from Proto-West Germanic sad, from Proto-Germanic sadaz (“sated, satisfied”), from Proto-Indo-European seh₂- (“to satiate, satisfy”). Cognate to stq sääd, West Frisian sêd, Dutch zat, German Low German satt, German satt. The interjection sense is a reference to frequent usage of the word as an interjection in the tweets of Q22686); a Trumpism#Noun.
Etymology from Wiktionary, CC BY-SA