asexual
a person who is not interested in or does not desire sexual activity, either within or outside of a relationship. asexuality is not the same as celibacy, which is the willful decision to not act on sexual feelings. asexuals, while not physically sexual-type folks, are none the less quite capable of loving, affectionate, romantic ties to others.  
while many women involved in so-called "boston marriages" had asexual relationships, their partnerships have none-the-less been claimed by some as part of lesbian history.