The word 'spellbinding' is a modern English compound formed from two distinct Old English roots. The first element, 'spell,' originally meant simply 'to speak' or 'to tell,' but its meaning narrowed over centuries to specifically denote the speaking of magical words or charms. The second element, 'bind,' retains its core sense of tying or holding fast. When combined with the adjectival suffix '-ing,' the literal meaning is "holding fast as if by a magical incantation." This vividly metaphorical construction perfectly captures the modern abstract sense of being so fascinating that one's attention is completely captured, as if under a magical spell.

Structure: spell (to charm) + bind (to tie) + ing (adjective suffix) - spell: From Old English spellian (to tell a story, to talk), later influenced by the sense of magical incantation. In this compound, it carries the sense of enchantment or magical charm. - bind: From Old English bindan (to tie, make fast). In this compound, it functions as a verb root meaning to hold or restrain. - ing: A suffix of Old English origin used to form present participles and adjectives from verbs, indicating a quality or state.