lengthen
v. B2 Upper Intermediate US //ˈɫɛŋkθən// UK //lˈɛŋθən// length·en
v. to make something longer or to become longer. You use this when talking about physical things like roads or time periods.
v. to increase the linear dimension of something; to extend in space or time. Often used in the context of physical expansion or the elongation of a period.
The sun will lengthen the shadows as it sets.
The architect decided to lengthen the hallway to provide more space for the new office furniture.
As the season progressed, the days began to lengthen, eventually reaching their peak duration just before the summer solstice.
From length + -en.