pseudoannual adjective 1noun 1forms 3 adjective1 •Having the appearance of something that occurs annually but not following a strictly annual pattern.In the pseudoannual rings of the root, the zones of tracheal tubes are separated from each other by rows of lignified tracheids. — 1933 noun1 •A pseudoannual species.These so-called pseudoannual species are characterized by the absence of a persisting shoot system that connects shoots longer than one vegetation period. One of these pseudoannuals is T. europaea. — 2009 formspseudoannuals · more pseudoannual · most pseudoannual