(adjective)
(informal) broadly, extremely careful, particular, neat, or precise in manner or behavior, almost to the point of fixation;
e.g. She thought they were being anal by bringing up such minor complaints.
(adjective)
(psychoanalysis) according to Freud's theories, the stage of an infant's/child's psychosexual development during which they are supposed most concerned with the anus and with defecation;
e.g. This behavior is thought to be typical of the anal stage of development.