adjective see: lean Date: 1833 inclined down from opposite directions so as to meet, having or relating to a folded rock structure in which the sides dip toward a common line or plane
SYNCLINAL
Meaning of SYNCLINAL in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012