Cross

Meaning
Burden, and the sense that it must be carried. The Cross is difficulty of a particular kind — hardship, grief, obligation, something heavy that cannot simply be put down. It also carries faith, fate, and belief in the traditional reading, and the two senses share a root: both concern what a person accepts rather than chooses.
The tone is sombre. The Cross is the deck's card of suffering, and it should be delivered carefully, especially to someone already struggling.
It is also, importantly, finite. A Cross is borne and then it is over, and readings frequently show what comes after it.
Beside other cards
Usually the modifier, weighting its neighbour with difficulty or significance. Cross + Ring is a burdensome commitment. Cross + Letter is hard news. Beside Sun, Star, or Key, look for what lightens it — those combinations are frequently about endurance leading somewhere.