Calejado means 'calloused' or 'hardened'. While it literally refers to skin that has become thick and tough from repeated friction, it's used metaphorically here.
In the song, the lyrics describe a 'coração ferido, triste, calejado' (a wounded, sad, calloused heart). This paints a vivid picture of a heart that has been hurt so many times it has become hardened and resistant to new love, making it a powerful and evocative word.
Vitor Fernandes is here to sweep you off your feet in "Esqueça Tudo"! This song is all about a new love trying to convince someone to leave their painful past behind. Our singer knows his love interest has been hurt, saying, "Eu sei que ainda é tão presente esse teu passado" [I know your past is still so present] and that their "coração ferido, triste, calejado" [heart is wounded, sad, calloused].
But don't worry, VF is here to save the day! He's confident that he's different from the ex who caused all that pain. He pleads, "Por favor, não me compara com esse vagabundo" [Please, don't compare me to that bum] and "não me compara com esse sem-futuro" [don't compare me to that good-for-nothing]. He promises to change their path, declaring, "Eu 'to chegando pra mudar seu rumo" [I'm arriving to change your direction]. It's a hopeful and passionate plea to forget everything and give love another chance!