1. (adjective) weak in willpower, courage or vitality

• gutless
• namby-pamby
• wishy-washy

2. (adjective) lacking a backbone or spinal column

• invertebrate

3. (adjective) lacking thorns

• thornless

1. (adjective) weak in willpower, courage or vitality

• weak

2. (adjective) lacking thorns

• unarmed

1. (adjective) lacking a backbone or spinal column

• zoological science
• zoology

1. (adjective) weak in willpower, courage or vitality

• namby-pamby
• spinelessness

1. (adjective) lacking a backbone or spinal column

• vertebrate

2. (adjective) lacking spiny processes

• spinous
• spiny