Request for permission.

A small amount at a time

A small amount at a time.

(informal) A step-by-step guide.

In detail, describing each step precisely and in order.

(idiomatic) (originally) by the authority or power of; (now) because of; on the grounds of; by reason of.

(construction) A length of lumber having a cross section of two inches by four inches, or in the case of dimensional lumber three and a half inches by one and a half inches.

measuring two inches by four inches / (by extension) small or cramped

(idiomatic) Describing things are handled more efficiently as a group, rather than individually.

Alone; without assistance or help from others. / Alone, without another's immediate company / (rare) Used other than figuratively or idiomatically: see by, oneself.