fill-in

[fil-in]

noun

1. a person or thing that fills in, as a substitute, replacement, or insertion.

   The company used a fill-in for workers on vacation.

2. a brief, informative summary; a rundown.

fill in

verb

1. (tr) to complete (a form, drawing, etc)

2. (intr) to act as a substitute

   a girl is filling in while the typist is away

3. (tr) to put material into (a hole or cavity), esp so as to make it level with a surface

4. informal,  (tr) to inform with facts or news

5. slang,  (tr) to attack and injure severely

noun

1. a substitute

2. informal,  a briefing to complete one's understanding

Word History and Origins

Origin of fill in¹

First recorded in 1915–20; noun use of verb phrase fill in

Idioms and Phrases

Complete something, especially by supplying more information or detail. For example, Be sure to fill in your salary history . It is also put as fill in the blanks , as in We'll rely on Mary to fill in the blanks . Yet another related usage is fill someone in , as in I couldn't attend, so will you fill me in? The first term dates from the mid-1800s; the others from the first half of the 1900s. Also see fill out .

Also, fill in for . Take someone's place, substitute for. For example, The understudy had to fill in at the last minute , or I can't come but my wife will fill in for me . Also see fill someone's shoes .