It involves the shortening of a longer word, often reducing it to one syllable. Many examples are very informal or slang.
Example
Maths, which is a clipped form of mathematics, is an example of this. Informal examples include 'bro' from brother and 'dis' from disrespect.
In the classroom
Discussion of clipping can help learners understand how words are formed in English, and will help learners understand authentic speech. One possible exercise to do this is for learners to identify the original words that have been clipped. Learners can also invent new clipped words.
Further links:
https://www.teachingenglish.org.uk/article/new-words-english