necess
Latinnecessary, need
About This Root
Necess- comes from Latin necesse 'unavoidable, inevitable,' and its noun necessitās 'an unavoidable need.' The most convincing breakdown is ne- ('not') + a form related to cēdere ('to yield, give way') — so the original picture is something that cannot give way, cannot be stepped around. A necessity is a wall you can't walk past; you must deal with it.
That single idea — 'no way around it' — runs through the whole family:
- necessary — something there is no avoiding; required
- necessarily (-ly) — as an unavoidable result; inevitably. You meet it most in the negative, not necessarily = 'it doesn't have to follow'
- necessity (-ity 'state of') — the state of being unavoidable, or the unavoidable thing itself (food and water are necessities)
- necessitate (-ate 'to make') — to make something unavoidable; to force it
The double 's' that trips up spellers comes straight from the Latin form necess-; there is no extra logic to it, you simply memorize that 'necessary' has one c and two s's (a useful mnemonic: a shirt needs one Collar and two Sleeves).
The family is small — there are no dramatic prefix branches the way there are with port or ject — but it is one of the most useful clusters in academic and everyday English, precisely because 'must,' 'required,' and 'unavoidable' come up constantly.
A necessity is a wall with no way around it (ne- 'not' + cēdere 'give way'). And remember the spelling: 'necessary' = one Collar, two Sleeves (1 c, 2 s).
Core Words Deep Dive
The few words from this family worth telling in full — one by one.
The anchor of the family: 'something there is no avoiding.' It works as an adjective ('a necessary step') and a noun ('the necessaries of life'). The tricky part is the spelling, not the meaning — one c, two s. Pair it with its opposite 'unnecessary' to lock both in.
Most often appears in the negative: 'not necessarily' = 'it doesn't automatically follow.' 'Expensive doesn't necessarily mean better.' Here the 'unavoidable' meaning is being denied — you're saying the link is not forced, not inevitable.
The verb: -ate 'to make' + necessity = to make something unavoidable. Formal and slightly impersonal — 'the storm necessitated a delay' is more detached than 'the storm forced a delay.' Common in reports and academic writing where the cause, not a person, does the forcing.