Colin has many possible meanings. It could be a form of the Gaelic "Caillean" which means "whelp" or "cub". It is sometimes defined as simply as "son". It is also an old French nickname for Nicholas, which means "Champion of the People".
Jeremiah means "Sent by God". Mom decided on Jeremiah quickly, and they decided it would make a good middle name. The verse: "Now the word of the LORD came to me saying, "Before I formed you in the womb I knew you, and before you were born I consecrated you; I appointed you a prophet to the nations. (Jeremiah 1:4)" has always been special to my Mom, and since she didn't know she was pregnant for 28 weeks, she believed that verse had special meaning for me.
One of the reasons my dad chose Colin for my first name was because he thought "CJ" would be a cute nickname. Once I was born, however, everybody called me Colin instead. Some of my family nicknames are "baby bear", "big 'un", and "Brutus"