symphonic

Etymology tree
Proto-Indo-European *sem-der.?
Proto-Hellenic *ksún
Ancient Greek σύν (sún)
Ancient Greek σῠν- (sŭn-)
Proto-Indo-European *bʰeh₂-der.
Proto-Hellenic *pʰōnā́
Ancient Greek φωνή (phōnḗ)
Ancient Greek -ος (-os)
Ancient Greek σῠ́μφωνος (sŭ́mphōnos)
Proto-Indo-European *-h₂
Proto-Indo-European *-éh₂
Proto-Indo-European *-i-eh₂
Proto-Hellenic *-íā
Ancient Greek -ῐ́ᾱ (-ĭ́ā)
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Ancient Greek σῠν- (sŭn-)
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Ancient Greek φωνή (phōnḗ)
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Ancient Greek -ίᾱ (-íā)
Ancient Greek -φωνίᾱ (-phōníā)
Ancient Greek σῠμφωνῐ́ᾱ (sŭmphōnĭ́ā)der.
Latin symphōniader.
Old French simphonieder.
Middle English symphonye
English symphony
Proto-Indo-European *-ikos
Proto-Italic *-ikos
Latin -icuslbor.
Old French -iquebor.
Middle English -ik
English -ic
English symphonic
From symphony + -ic.