Condition involving increased stem elongation. poor leaf development. and a lack of chlorophyll; found in plants growing in the dark or with greatly reduced amount of light
etiolation (Wikipedia)
Etiolation /iːtiəˈleɪʃən/ is a process in flowering plants grown in partial or complete absence of light. It is characterized by long, weak stems; smaller leaves due to longer internodes; and a pale yellow color (chlorosis). The development of seedlings in the dark is known as "skotomorphogenesis" and leads to etiolated seedlings.