Definition of subthalamus in US English:

subthalamus

noun

Anatomy
  • Originally: the subthalamic nucleus (now rare). In later use: a region at the base of the forebrain located between the dorsal thalamus and the hypothalamus, containing the subthalamic nucleus, several other nuclei, and tracts of fibres; the ventral thalamus.

Origin

Late 19th century. From sub- + thalamus. Compare earlier subthalamic.

Pronunciation

subthalamus

/ˌsʌbˈθaləməs/