This means to make yourself look low and useless in front of someone else, like begging.

You should never humiliate yourself in front of anybody EXCEPT Allah, because HE is the only one to whom we should beg. When you humiliate yourself, you lose your dignity, and show that you have little self respect.

Imam Husain (A) was once approached by a beggar for some money. Imam (A) told the treasurer to pay him one thousand Ashrafi (gold coins of the time).

The beggar took the money, but instead of going away with it, he sat down to count and check every coin. When he was asked why he was counting, the beggar replied, "Why not, I have sold my DIGNITY in begging."

On hearing this, Imam (A) said it was true, and ordered another thousand Ashrafi to be paid to him. When the beggar had counted and taken possession of two thousand coins, Imam (A) took a further thousand Ashrafi and gave it to the beggar, and uttered these words,

"The first thousand Ashrafi is in response to your begging, the second thousand Ashrafi is in RETURN for your DIGNITY, and the third thousand Ashrafi is for your visit, and coming to see me instead of going elsewhere to ask for help."

This shows, besides the generosity of Imam (A), that even the beggar has honour and dignity, and should never be humiliated by the giver. On the contrary, the giver should be thankful, since because of the beggar, he has earned something worth much more than money, ...Thawaab.

When someone belittles (makes himself look small) himself, he is ridiculed and lacks courage.

Imam Jaffer As-Sadiq (A) has explained:
"Indeed, God has left to a believer all his dealings, except to belittle himself, for hasn't it been stated in the Qur'an, "But for God is ALL HONOUR and for HIS Apostle, and for the believers, but the hypocrites know it not."

A lot of people in the world belittle themselves because they want something from other people, eg. if the boss makes a joke about you in front of people, and you just sit there, then you are belittling yourself just so that your boss can laugh.

Allah has made all men equal. Therefore, if you humiliate yourself for someone else, you think that person is greater than you. This means that by humiliating yourself for his money, or power, you are worshipping him. As a result you are bringing him on the same level as Allah, and that is becoming MUSHRIK (believing in more than one God.)