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

Example Sentences

With nearly endless research suggesting that constant smartphone use is making our memories worse, it makes sense that technology would try to fill in the blanks.

From Slate

Sometimes they show that they don’t know what they don’t know, and fill in the blanks in their knowledge with fabrications — or as AI developers call them, “hallucinations.”

From Los Angeles Times

Or a person with this affliction will just make words up to fill in the gaps.

From Salon

Sanchez said he often ends up working six or seven 12-hour shifts weekly because it’s hard to find a guard willing to fill in for him on weekends.

From Los Angeles Times

Can you fill in the details here?

From Slate

Related Words

• fill out
• insert