first thing

adv, noun — 4 senses

first thing

adv

1

Early in the morning.

I'll meet you first thing at the station.

2

Straight away, very soon.

Some of 'em said that when a boy had been away from home a couple of years he ought to want to see his folks the first thing.1916 March 11, Charles E. Van Loan, “His Folks”, in Saturday Evening Post:
I'll do it first thing after school tomorrow.2009, Alex J. Packer, Bringing Up Parents: The Teenager's Handbook, →ISBN:

2 more examples

You had to see it first thing, 'cause it was the first thing that caught the eye.2012, Cd Harper, And Face the Unknown: The Journey of a Lincoln-freed Colored, →ISBN:
Whatever it is, getting it out of the way is crucial to your forward momentum. So, to borrow a phrase from Nike, just do it—and do it first thing.2013, Nelson Searcy, Jennifer Dykes Henson, The Renegade Pastor: Abandoning Average in Your Life and Ministry, →ISBN, page 2013:

first thing

noun

1

In the negative The basic idea of how to do something.

I would help you, but I don't know the first thing about gardening.

2

Used other than figuratively or idiomatically: see first, thing.

I stumbled along through the young pines and huckleberry bushes. Pretty soon I struck into a sort of path that, I cal'lated, might lead to the road I was hunting for. It twisted and turned, and, the first thing I knew, made a sudden bend around a bunch of bayberry scrub and opened out into a big clear space like a lawn.1913, Joseph C[rosby] Lincoln, chapter I, in Mr. Pratt’s Patients, New York, N.Y.; London: D[aniel] Appleton and Company, →OCLC:

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.