I thought her explanation was perfectly/entirely/completely 'plausible'. [=I believed her explanation]
a 'plausible' [='possible'] conclusion
a 'plausible' excuse
(..) Shmear me. Well,here's an interesting turn of events. What? Howard brought a date? A more plausible explanation is that his work in robotics has made an amazing leap forward. Hey,what up,science bitches? May I introduce my special lady friend summer? Howard,I told you touching's extra. (..)2007 TvShow: The Big Bang Theory Title: The Luminous Fish Effect Season: 1 Episode 4