Student or Learner
he kept the flower beds in meticulous order, even though kneeling was difficult and getting up was even more so.
what does the underline sentence mean?
It means that he found it difficult to kneel down (or to remain in a kneeling position) and it was even more difficult for him to stand up from that kneeling position.
Note that there was no need to put the part you were querying both in bold and to underline it. Underlining it was sufficient. "Underline" is a verb. "Underlined" is the associated adjective. Remember to start every sentence with a capital letter.
Also please note that I have changed your thread title. Titles should include some/all of the words you are querying.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.