Safe one 

This is a confused attempt to combine the word 'safe' with the phrase 'nice one'. Usually blurted out in pressure situations in the company of intimidating individuals.

Intimidating individual- "There you go bruv"

You- "errr... safe one"

Safe one by Aliensuns May 28, 2009

Safe one 

An almalgamation of the phrases 'safe' and 'nice one' this common used phrase has it's roots in Cambridge surburbia, but is found in all areas of the UK

Tali: "I did like a million pieces of work today!"
Tom: "Safe one babes"

Safe one by twg1993 May 2, 2011