godan verb (-ru), transitive verb
daub thickly; slather on; paint heavily
Implies applying a substance (paint, cream, etc.) thickly, messily, or excessively. Often has a negative or exaggerated nuance.
壁にペンキを塗りたくる。
I slather paint on the wall.
彼女はパンにバターを塗りたくる。
She spreads butter thickly on the bread.
Standard kanji-kana spelling.
Kana spelling used for emphasis or in casual writing.
塗る is the neutral verb for 'to paint' or 'to spread'. 塗りたくる adds a sense of doing so thickly, messily, or excessively.
Compound of 塗り (continuative form of 塗る 'to paint') + たくる (suffix meaning 'to do vigorously or repeatedly').