semi

word

/ˈsɛmaɪ/
/sˈɛmi/

Definition

'Semi' can mean a large truck with a trailer (especially in the US), or it can be a prefix meaning 'half' or 'partly' (as in 'semicircle').

Usage & Nuances

As a noun, 'semi' (short for 'semi-trailer') is common in American English for big trucks. As a prefix, it attaches to other words ('semi-final', 'semicircle') to mean 'half' or 'partial'. In the UK, 'semi' alone can also mean 'semi-detached house' (house sharing a wall). Context determines the meaning.

Example Sentences

A semi drove past our house last night.

basic

The shape is a semicircle.

basic

He reached the semi-final of the tournament.

basic

Be careful driving near semis on the highway.

natural

My parents live in a semi outside London.

natural

He only has a semi understanding of the topic.

natural