To extend or to lengthen
The base word for lengthen is long > length > lengthen
Lengthen is a verb.
Stretching the rubber band would lengthen it. It is the sentence containing the lengthen word.
The noun forms for the verb to lengthen are lengthener and the gerund, lengthening.The word lengthen is the verb form of the noun length.
accelerate means to increase speed.
lengthen
Verb
"Crescendo", means to gradually increase in size, intensity or force.
slowing
elongate
pickles