The child buried his head in his mother's lap.

buried 是动词 bury 的过去式，意思是"埋、掩埋"。 his 是代词 he 的所有格形式，意思是"他的"。 head 是名词，意思是"头、头部"。 in 是介词，表示"在...里面"的状态。 buried his head in... 这个短语描述的是"把头部埋进..."的动作，常用于表达害羞、哭泣或寻求安慰时的肢体动作。