wear something on one's sleeve

Meaning

Verb

• To express an emotion, belief, or stance overtly and make it an important part of one's public life.

Origin

• This phrase may derive from a mediaeval custom at jousting matches. Knights are said to have worn the colours of the lady they were supporting, in cloths or ribbons tied to their arms.
• The term does not date from that period though, and is first recorded in Shakespeare's Othello, 1604, in which the treacherous Iago's plan was to feign openness and vulnerability in order to appear faithful
• : Iago:
• : It is sure as you are Roderigo,
• : Were I the Moor, I would not be Iago:
• : In following him, I follow but myself;
• : Heaven is my judge, not I for love and duty,
• : But seeming so, for my peculiar end:
• : For when my outward action doth demonstrate
• : The native act and figure of my heart
• : In compliment extern, 'tis not long after
• : But I will wear my heart upon my sleeve
• : For daws to peck at: I am not what I am.
• .