Idiom: Be Someone's To LoseCheck definitions of...besomeonestoloseMeaningsTo be anticipated to be won by someone.Used other than figuratively or idiomatically: see be, someone's, to, lose.A-Z Proximitiesbe motherbe my guestbe one's own worst enemybe oneselfbe on to be someone's to lose be still my heartbe supposed tobe taken illbe that as it maybe thereSimilar Idiomsbe someone's to loselose facelose groundlose itlose one's coollose one's headlose one's mindlose one's shirtlose one's temperlose one's touchlose one's witslose the belllose the number of one's messlose touchwin the battle, but lose the warSimilar Phraseslose itlose sight oflose trackbreak someone's heartin someone's waypull someone's legsell someone outtake someone's side