"Koshi" is the Japanese term for hip. It is used to describe the curve of a line usually in upright arrangements. 

Example #1: "That Shoka flower arrangement has a really nice koshi, don't you think?"

Example #2: "Does my koshi look OK in this dress?"

Shiun Ikebana Container with Kubari
"Kubari" is the Japanese word for sticks used to create a division or grid in the interior of a vase or container. The sticks are used to support and anchor the flower and plant materials in an arrangement. In this image, the Kubari are being used to hold the material (Pussy Willow) upright in the center of the container.

In very traditional Ikebana arrangements, the Kubari is used alone. In the image below, you can see the Kubari is being used in combination with a Kenzan. This is not, however, typical.

Closeup of Y Kubari
In the image to the right, the Kubari is in the shape of the letter "Y" (called Y Kubari in America). Here it is being used to hold the floral materials in a straight line for a Shoka style arrangement.

The word Hana in Japanese means flower.
Kaki is the Japanese word for "flower vase" or "container to hold flowers".
kenzan naoshi pin frog straightening tool for ikebana
Kenzan Naoshi is the Japanese word for this tool. It is used to straighten bent pins in the kenzan (pin frog) when they are forced out of alignment by particularly tough woody materials used in an arrangement.

kenzan pin frog needle point holder
Kenzan, litterally "sword mountain", is the Japanese term used to refer to a "needle point holder" or "pin frog". The Kenzan is used to hold flowers and other plant materials in place when making an arrangement. The plant materials are cut at an angle using the hasami (shears), then inserted into the pins for placement. Kenzan are available in many different sizes, shapes, weights and needle sizes. 

hasami ikebana scissors or shears
Hasami is the Japanese word that refers to a type of scissors or shears used in ikebana to trim and cut plant materials. They are very sturdy and sharp making them ideal for cutting woody shrubs and branches.

The word ikebana comes from the two Japanese words ike from the word ikeru meaning "to make live" and bana from the word hana meaning "flowers." The best english translation may be "making flowers come alive."