Intensigender is a gender where one feels very and completely sure that they are a certain gender and have always known that they are this gender. Someone who is intensigender may add the gender they are sure they are to the label "intensigender." For example, labeling themself transmasc intensigender. Intensigender people may feel like they are more than 100 percent a certain gender. They may feel as if they are 120 percent, 150 percent, etc.
Intensigender isn't always LGBTA+
Cisgender individuals may identify as intensigender. This is valid, but does not in and of itself denote that an individual is LGBTA+ (unless of course there are overlapping LGBTA+ identities such as homosexual, bisexual, ace-spec, etc).