▁is ▁often ▁included ▁in ▁longest - word ▁lists . ▁ ▁Long est ▁word ▁candidates ▁may ▁be ▁jud ged ▁by ▁their ▁accept ance ▁in ▁major ▁diction aries ▁such ▁as ▁the ▁Oxford ▁English ▁Dictionary ▁or ▁in ▁record - keep ing ▁publications ▁like ▁Gu in ness ▁World ▁Records , ▁and ▁by ▁the ▁frequency ▁of ▁their ▁use ▁in ▁ordinary ▁language . ▁ ▁A gg l ut in ative ▁L anguages ▁ ▁Bas que ▁ ▁The ▁longest ▁Bas que ▁to pon ym ▁is ▁ ▁( 4 0 ). ▁ ▁Es per anto ▁ ▁The ▁longest ▁official ▁Es per anto ▁roots ▁are ▁ 1 3 ▁letters ▁long , ▁shown ▁here ▁with ▁the ▁added ▁substant ive ▁"- o " ▁ending : ▁▁ ▁( admin istration ), ▁ ▁( aut obi ography ), ▁ ▁( dis c rim ination ), ▁ ▁( con serv atory ), ▁ ▁( p ala e ont ology ), ▁ ▁( par alle lo gram ), ▁and ▁ ▁( tr ig on ometry ). ▁ ▁Since ▁Es per anto ▁allows ▁word ▁comp ounding , ▁there ▁are ▁no ▁limits ▁on ▁how ▁long ▁a ▁word ▁can ▁theoret ically ▁become . ▁A ▁relatively ▁short ▁example ▁is ▁the ▁ 4 6 - letter ▁, ▁which ▁is ▁an ▁( acc us ative ▁and ▁pl ural ) ▁ad jective ▁that ▁means ▁" about ▁to ▁begin ▁to ▁become ▁the ▁leader ▁of ▁a ▁cont empt ible ▁p ala e ont ology ▁conserv atory ". ▁( S uch ▁clusters ▁are ▁not ▁considered ▁good ▁style , ▁but ▁are ▁perm iss ible ▁under ▁the ▁rules ▁of ▁Es