dark and sticky, like treacle

He'd coated the shelves with a thick treacly varnish. 他给架子涂了厚厚一层糖蜜似的罩光漆。

too pleasant or kind, or expressing feelings of love in a false way

The film is spoilt by a slightly treacly sentimentality. 这部电影的败笔在于有点儿过分煽情。