Here are the dictionary definitions:
no longer be in possession of; get rid of
be cut from being together, e.g. due to seperation or death
not be able to hold on to with the hands due to negligence, a sudden movement, lack of power etc. (that is, to drop something)
come out of a match, a wager, a war or other conflict or competition as the weakest party; suffer defeat (that is, to lose a game/match/war etc.)
There are also more definitions for at tabe, but these are the most relevant.
- lose the right or opportunity to obtain something (used in formal language). (for example: "Da han flyttede ud af landet, fortabte/mistede han retten til sundhedspleje" = "When he moved out of the country, he lost the right to healthcare")