The outspoken 55

By Snejana Farberov

PUBLISHED: 01:28 EST, 18 January 2014 | UPDATED: 02:34 EST, 18 January 2014

Madonna has never been afraid to express herself, but now she may have gone a step too far.

The outspoken 55-year-old entertainer landed in hot water Friday evening after using the N-word in a caption that accompanied a photo of her son she had shared on Instagram.

In the image that appeared on the account that purportedly belongs to the singer, her 13-year-old son Rocco Ritchie is seen in training in a boxing ring.

The proud mother of four commented: 'No one messes with Dirty Soap! Mama said knock you out! #disn****'

The offensive hashtag sparked outrage among some of her fans, prompting Madonna to take down the caption just minutes later.

However, the Material Girl was manifestly unapologetic about using the racial slur.

She replaced her previous comment with a foul-mouthed message addressed to her critics: 'Ok let me start this again. # get off my d*** haters!'

Some of her one million followers ripped into the superstar for her use of the offensive term.

One commenter wrote: 'MADONNA U NEED TO TAKE UR arthritis medicine instead of trying to be hip on the internet.'

'Spreading ignorance is awful!' another user noted.

But thousands of Madge's loyal fans quickly came to her defense.

One supporter of the singer and filmmaker even went so far as to say that she deserves a pass for using the N-word because she 'has basically adopted half of Africa,' Vibe.com reported.

Madonna has two children she has adopted from Malawi, David Banda and Mercy James, both 8 years old.

She had her son Rocco with her former husband, director Guy Ritchie, in 2000. She also has a 17-year-old daughter, Lourdes Maria Ciccone Leon, from a previous relationship with Cuban-born personal trainer Carlos Leon.

The kerfuffle over the N-word hashtag comes less than two weeks after Madonna posted another photo featuring her 13-year-old son brandishing a bottle of 94-proof Bombay Sapphire gin.

'The party has just begun! Bring it! 2014,' the pop diva gushed on her Instagram account.

The image of the minor clutching a bottle of hard liquor along with a couple of friends displaying Belvedere vodka was taken in Switzerland, where the legal drinking age is 16.