What does the cryptic crossword clue "Somewhat user-friendly one is bound to work (4)" mean?

The definition is "Somewhat". The wordplay uses a hidden word. A hidden answer (‘somewhat’) in ‘u SER-F riendly’. The answer is SERF.

Somewhat user-friendly one is bound to work (4)

Guardian Cryptic #29415 | 12 Across | 2024-06-21 flower