noun

an unfavourable circumstance or condition that reduces the chances of success or effectiveness.

a major disadvantage is the limited nature of the data

drawback,snag,downside,stumbling block,catch,pitfall,fly in the ointment,weak spot/point,weakness,flaw,defect,fault,handicap,limitation,trouble,difficulty,problem,complication,liability,nuisance,hindrance,obstacle,impediment,disbenefit,minus,hiccup,spanner in the works,monkey wrench in the works

verb

put in an unfavourable position in relation to someone or something else.

the pension scheme tends to disadvantage women

treat unfavourably,put at a disadvantage,treat harshly/unfairly,handicap,inflict a handicap on,do a disservice to,be unfair to,wrong