“My other half” and “my significant other” are two phrases that basically point to the same sort of thing: husbands, wife, girlfriend, boyfriend, or some sort of longterm life partner. Superficially they look the same, because they are used interchangeably, and also because they share the word “other”, but if we look at them they can mean very different things.
“My other half” is the person that completes me, someone that compensates my shortcomings, and vice versa. Without them I cannot live a full life, and can never be a person in my own right. Together we form two functions within a wholeness, but it cannot be called a relationship because we are not two wholenesses interacting with each other.
“My significant other” is someone in my life who is not me, who does not complete me but is important in my life; significant. We do not supplement each other’s personalities, we don’t need to. I may need you to cement the house, and you may need me to paint it, but that’s not for lack of wholeness; it’s simply because our skills are complementary, and we are working as a team, not serving co-dependent functions.
Personally I like “significant other” because that means there is an Other to have a relationship with. “Other half” isn’t a relationship, it’s a arrangement, my lungs aren’t in relationship with each other, they are organs that form functions for a whole (my body). A relationship happens between two wholenesses, two individuals that have their own thoughts and feelings. They can interchange skills and be a balance in the life of the other without completing each other.
Since I am in a relationship with “my significant other” and not “my other half”, where exactly is “my other half”? That’s a question for another time. 😀