spec·tro·he·li·o·gram 
(spĕk′trō-hēlē-ə-grăm′)
(spĕk′trō-hēlē-ə-grăm′)n.
A photograph of the sun taken in a narrow wavelength band centered on a selected wavelength.
- unflaggingly
- unflappability
- unflappable
- unflappably
- unflapped
- unflattering
- unflatteringly
- unfledged
- unflinching
- unflinchingly
- unflinchingness
- unfocused
- unfocussed
- unfold
- unfoldment
- unforeseen
- unforgettability
- unforgettable
- unforgettableness
- unforgettably
- unforgivable
- unforgiving
- unformatted
- unformed
- unfortunate