toothbrush tree: glabrous or pubescent evergreen shrub or tree of the genus Salvadora; twigs are fibrous and in some parts of the world are bound together in clusters and used as a toothbrush; shoots are used as camel fodder; plant ash provides salt
organism: a living thing that has (or can develop) the ability to act or function independently
breaststroke: a swimming stroke; the arms are extended together in front of the head and swept back on either side accompanied by a frog kick