Regex , find match and get text just before the next match

[Pirate]

Say i have this text (from dictionary) :

knife n 1: edge tool used as a cutting instrument; has a pointed blade with a sharp edge and a handle 2: a weapon with a handle and blade with a sharp point 31: any long thin projection that is transient; "tongues of flame licked at the walls"; "rifles exploded quick knives of fire into the dark" [syn: {tongue}] v : use a knife on; "The victim was knifed to death" [syn: {stab}] [also: {knives} (pl)] .

I want to use regex to be able to put every definition on new line . Like so :

knife n
1: edge tool used as a cutting instrument; has a pointed blade with a sharp edge and a handle
2: a weapon with a handle and blade with a sharp point
3: any long thin projection that is transient; "tongues of flame licked at the walls"; "rifles exploded quick knives of fire into the dark" [syn: {tongue}] v : use a knife on; "The victim was knifed to death" [syn: {stab}] [also: {knives} (pl)]

I used this pattern "\s[1-9]+\x3A\s" to find number of definitions but i don't know how to select the match " n: " along with the word definition (just exactly before the second match occurs).

Any regex guru ?