1rare Relating to or constituting a climacteric; = "climacteric"; especially relating to or constituting a grand climacteric.
"climacterical year": = "climacteric year"; specifically the 63rd year of a person's life.
2Critical, decisive; subject to significant or frequent changes.
Late 16th century; earliest use found in Thomas Fortescue (d. 1602), translator and alleged sorcerer. From classical Latin clīmactēricus climacteric + -al.