I note that you chose definition number three, as in most dictionaries the first definition listed is to hold an opinion without facts or logical support. So you are even willing to be duplicitous in that. Your guilty conscious makes a genetic cause for homosexual behavior neither more nor less likely. It is not a rational basis for that declaration. There is a mountain of evidence that human sexual attraction develops during puberty in most adults, and can be shaped by personal experience. No appeal to genetics is necessary. Occam’s Razor. The genetic attribution is political in nature. It always has been.
Regarding your dictionary “placement” thinking, look up number one for the word “bigot.”