i Register
In some senses, sec is marked as informal, colloquial, US. Watch for register when choosing this word.
ADJ.
alone, sorry
I'll just be a sec alone in the office to finish this report.
VERB + SEC
back, give, hang, hold, names, phone, see, take
Hold on a sec, I need to find my keys before we leave.
SEC + NOUN
m, s
The meeting lasted five minutes and forty-five secs total.
PREP.
in, on
Hold on in sec, I need to grab my wallet before we leave.
ADV.
such
Hold on a sec, such a great idea just popped into my head.