“sporadically”

After reading “Sweat” by Zora Neale Hurston I came a really unfamiliar word and that was “sporadically”, it was used as “she sporadically finished her education” I assumed that it must have meant slowly sine it was mention something about education and finishing it, so I basically used context clues but I went to Merriam Webster dictionary and found out it means ” not regularly or constantly” which was close to what I thought it meant. I now feel like an expert when using context clues since it was really close to the exact definition of the word but most importantly now what it really means.