Amorous describes feelings, looks, and behaviour that show sexual love — wanting someone in that warm, bodily, romantic way, not only liking them as a friend. An amorous glance, amorous letters, amorous adventures. It is not the word for a parent’s love or for being a kind classmate. The tone is a little literary and a little old-fashioned; younger people more often say flirty, or they use blunter words. In a modern office it can sound like a line from a novel, which is sometimes the point. It can also be slightly comic: “amorous adventures” comes with a wink. Though actually, older books sometimes use it more gently for being in love; today you should assume there is desire in it, not only sweet affection.