【Embarrass】 , 【discomfit】 ,  【abash】 ,  【disconcert】 ,  【rattle】 ,  【faze】  mean to balk by confusing or confounding, but each word is capable of expressing precise and distinctive shades of meaning.

【Embarrass】 characteristically implies some influence which impedes freedom of thought, speech, or action and may be used with reference not only to persons but also to the things they plan or desire to do.

When said of persons it commonly implies and often stresses resulting uneasiness or constraint.

【Discomfit】 in this sense typically retains some of its basic denotation of to put to rout; in such use it implies opposition and the competence with which one opponent routs the other and crushes his self-esteem or self-complacency or throws him into confusion or, sometimes, thwarts his wishes, his hopes, or his plans.

At times  【discomfit】 is used with much weakened force and then loses its suggestion of active opponency and implies no more than to make uncomfortable or 【embarrass】 .

【Abash】 presupposes self-confidence or self-possession and implies a usually sudden check to that mood by some influence that awakens shyness or a conviction of error or inferiority or, sometimes, of shame.

【Disconcert】 , like  【embarrass】 , may be used in reference to actions and plans, but it is more frequently referred to persons. In either case it implies an upsetting or derangement; in the latter it suggests temporary loss of equanimity or of assurance.

【Rattle】  more than  【disconcert】 stresses the emotional agitation accompanying the upset and implies a more complete disorganization of one's mental processes.

【Faze】  is found chiefly in negative expressions, where it comes close to  【disconcert】  but sometimes carries the implications of  【abash】  and  【rattle】 .