To commit a sin that can invite the curse of Allah Subhanahu waTa'ala. The Prophet sallallaahu 'alaihi wasallam said,
"Allah cursed the tattooed woman and asked for the tattoo, the woman who shaved her eyebrows and who asked for her eyebrows shaved, the woman who exposed her teeth to be beautiful to change the creation of Allah." (Muttafaq 'alaih)
"Allah cursed the woman who connected her hair or asked for her hair