IPA: /ʌnˈsplɪt/
KK: /ʌnˈsplɪt/
Not divided into parts; remaining whole or intact.
The unsplit log was perfect for the fireplace.
Unsplitting is formed from 'un-' (meaning not) and 'split' (from Old English 'splittan', meaning to divide or separate). The word 'unsplit' means not divided or separated.
Think of 'not' ('un-') dividing or separating ('split') something — that's why unsplit means something that remains whole.