yn ystod

== Welsh == === Preposition === yn ystod during, within a time interval during, throughout ==== Synonyms ==== yn oed === References === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “ystod”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies