類洞 is read as るいどう (ruidou) and means sinusoid.
るいどう
ruidou
るいすい
analogy
るいじんえん
anthropoid ape
るいぎせい
quasi-synonymy
るいすいてき
analogical
るいすいすいり
reasoning by analogy
るいぎご
similar words
るいごじつようじてん
thesaurus published by Sanseido
るいぎ
synonymy
るいじせいひん
lookalike (product)
るいぎごじてん
thesaurus
るいごじてん
るいじゅう
assembling according to type