1) Couple 2) Join poorly 3) Join wrongly 4) Marry unsuitably 5) Match 6) Mate 7) Mismatch 8) Pair 9) Select unlike socks 10) Twin 
• (v. t.) To mate wrongly or unsuitably; as, to mismate gloves or shoes; a mismated couple.
Mis·mate' transitive verb To mate wrongly or unsuitably; as, to mismate gloves or shoes; a mismated couple. 
[v] - provide with an unsuitable mate
A drug given in attempt to prevent pregnancy.