To look carefully or with difficulty. (Cambridge Dictionary)
One that is of equal standing with another: Equal. (Merriam – Webster)
Look with difficulty or concentration at someone or something. (Oxford Dictionaries)
If you peer at something, you look at it very hard, usually because it is difficult to see clearly. (Collins Dictionary)
Differences Between Colleagues and Peers.
Colleagues to you is anyone in the same workplace whereas peer is one who is on the same status with you.
What is peer pressure?
Making good mates is important, but sometimes trying to fit in with a group can turn sour. Giving in to pressure from your friends to do something you normally wouldn’t do can leave you feeling guilty, regretful, ashamed, embarrassed or even frightened. Find out what peer pressure is and how to handle it, including what to do if things get serious.